Abstract: This chapter surveys the developing debate in comparative constitutionalism over American exceptionalism, whether the United States differs in kind from other constitutional democracies on important dimensions and, if so, what might explain that divergence. The United States is distinctive in the distinctive ways in which racial concerns and politics have influenced American constitutional development and contemporary doctrine. On those constitutional issues on which the United States differs most form other constitutional democracies, most notably free speech, racial concerns best explain why the United States took a different path than such nations as Germany, Canada and South Africa. These observations highlight the importance of incorporating constitutional politics, the political struggles to make particular constitutional visions the official law of the land, into comparative constitutionalism. What too often appear from the perspective of comparative constitutional law to be isolated doctrines or academic theories of the judicial function often have an underlying structure better explained by political struggles to construct constitutional law and aspirations than commitments to values abstracted from politics. For the past half-century, the constitutional politics of race have influenced the path of American constitutional law. Race in other regimes has not nearly had the same influence, or in the case of South Africa, racial concerns have pushed constitutional politics in different directions from that of the United States.